The present invention relates to the relubrication or recharging with lubricant of bearings of rotating members as used, for example, in conveyors and drives of mobile agricultural machines such as crop harvesters and the like, and especially to relubrication of self-contained idler bearings used in such machines.
In agricultural machines, many bearings are required to operate in environments where any bearing sealing means is subject to damage and deterioration from contaminants, such as dust and moisture, or abrasive mechanical action from crop material being handled and/or soil particles disturbed by operation of the machine. In such conditions, it is not generally possible to provide seals completely effective in protecting bearings and in retaining lubricant and it becomes desirable to relubricate or recharge the bearing internally to extend its life. Preferably, this is done in situ without disassembly. In an idler assembly, for example, comprising an outer member journaled on an inner member, a common arrangement uses a special mounting bolt for securing the assembly to a frame member of a machine, the bolt being drilled and tapped and fitted with a conventional grease fitting. Thus, grease can be forced into the idler bearing by way of the drilled bolt passages and a cross-drilled passage in the inner member or race of the idler itself. Forcing lubricant, under pressure, into the cavities of the idler bearing recharges the bearing with lubricant and may flush contaminants out of the bearing area and clear of the surfaces wiped by bearing seals.
However, the drilling and cross-drilling of mounting bolts or studs or idlers is, in itself, relatively expensive and a variety of sizes and lengths must be provided to suit various installations and types of idler, potentially resulting in a significant extra inventory cost. Also, the nature of the drilled stud or bolt substantially limits the position of the grease fitting for recharging the bearing to being on an end of the stud, unless additional cost is incurred in drilling and machining special forms for the stud. A simple axial end position for the grease fitting does not always provide most convenient access for the relubrication operation.